Begin by crushing the Oreo cookies into fine crumbs. You can use a food processor or a plastic bag and a rolling pin to crush them. Set aside about 1/4 cup of the crumbs for later.
In a mixing bowl, beat the 1 1/2 cup cream until soft peaks form. Add the 1/4 cup powdered sugar and 1 tsp vanilla and continue to beat until stiff peaks form. Set aside.